Fluid-packed drill collar



April 20, 1965 F. D. DE JARNETT FLUID-PACKED DRILL COLLAR 3 Sheets-Sheet 1 Filed Sept. 28, 1962 r m a O 6 U M M 3 w BB L d 3 3 M W W4 M 4% 7 r 4 ATM/(Ma awake/V577, aw

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Apnl 20, 1965 F. D. DE JARNETT FLUID-PACKED DRILL COLLAR Filed Sept. 28, 1962 April 20, 1965 F. D. DE JARNETT FLUID-PACKED DRILL COLLAR 3 Sheets-Sheet 3 Filed Sept. 28, 1962 MW M ww w /J 4 F- Q M M w 3 W 1 2 United States Patent 3,179,188 FLUID-PACKED DRILL COLLAR Frank D. De Jarnett, 2150 Chestnut Ave, Long Beach, Calif.

Filed Sept. 28, 1962, Ser. No. 226,918 4 Claims. (Cl. 175-320) My invention relates to improvements in fluid-packed drill collar, and particularly their application to the use of rotary tools, where a bit designed to cut in rotary motion is carriedon a string of drill pipe which is assembled in such manner that it may be rotated and raised or loweredin the well bore as desired; and the objects of my invention are, first, to provide a novel type of fluid packed drill collar which will minimize structural failures caused by vibration and particularly by harmonic vibrations and shock transmitted from the rotary bit along the assembled drill collars and drill pipes; second, to provide a fluid-packed drill collar which will stiffen an assembled string of drill pipe and drill collars, and will add weight to such string of drill pipe and drill collars; third, to provide a fluid-packed drill collar combining the use of fluid and a plurality of steel sleeves placed about the inner steel tube, thereby acting as a stabilizing element between the inner and outer tubesgand fourth, toprovide a fluid-packed drill collar, which is easily assembled and manufactured, and wherein the weight may be predetermined depending on the type of packing in combination with the type of fluid to be used. Reference is made to my United States Letters Patent No. 2,814,462, issued November 26, 1957, for its description of the causes of vibration and shock in connection with the functioning of a drilling bit.

Additional objects, together with further advantages derived in utilizing the present invention, will become apparent from the following detailed description thereof taken together with accompanying drawing forming part of the specification, in which FIGURE 1 is a partial diagrammatic vertical section of a typical assembled string of drill pipe and drill collars using my invention;

FIGURE 2 is a cross-section of a drill collar as used in the drill collar assembly as shown in FIGURE 1;

FIGURE 3 is a transverse section taken on line 33 of FIGURE 2;

FIGURE 4 is a cross-sectional view of my drill collar using a plurality of fixed sleeves and longitudinally slidable spacers, disposed alternately between sleeves;

FIGURE 5 is across-section of a drill collar using a combination of a plurality of sleeves of varying diameter with fluid packing between the inner and outer tubes;

FIGURE 6 is a transverse section taken on line 6-6 of FIGURE 5 FIGURE 7 is a partial cross-section of a modified form ofmy drill collar, using a plurality of fixed sleeves and lltingitudin'ally slidablespacers mounted about the inner steel tube, and disposed between a tube extension and a tool joint pin having the same outside diameter as the outer steel tube;

FIGURE 8 is a cross-section of a modified form of my drill collar, using a rubber or asphalt filler to fill the annula space between the inner steel tube and the outer steel tube, disposed about each other and fixed in position between a tube extension having the same outsiderliann ice eter as the inside diameter of the outer steel tube and a tool joint pin;

FIGURE 9 is a transverse section taken on line 9-9 of FIGURE 7;

FIGURE 10 is a transverse section taken on line 10- 10 of FIGURE 7;

FIGURE 11 is a transverse section taken on line 11-11 of FIGURE 8;

Similar numerals refer to similar parts throughout the several views.

The invention described in FIGURES l, 2, and 3 of the accompanying drawing comprises a fluid-packed drill collar used in connection with an assembled string of drill pipe and drill collars arranged as shown in FIGURE -l, which illustrates schematically an oil well bore, 19,

in which an assembled string of drill pipes, 11, and drill collars, 12, carrying a rotary bit, 13, is designed to rotate in the manner well known to the art by means of the rotary table, 14, of a drilling unit located at the top of the well bore, 10. The individual drill collar, approximately 30 feet in length, as illustrated in FIGURES 2 and 3 of the accompanying drawing, comprises an inner steel tube, 20, surrounded by an outer steel tube, 21, which together form a fluid-tight annular space, or chamber, 22.

o The upper end of the inner steel tube, 20, is threaded into a tubular extension joint, 25, in a fluid-tight manner, as for instance, by threading the inner tube, 20, into the extension joint, 25, while the extension joint is heated so that the extension joint, 25, will shrink into a pressure fit with the inner steel tube, 29. The outer steel tube, 21, is fastened to the extension joint, 2.5, by welded joint, 26

The lower end of the inner steel tube, 20, is threaded into a tool joint pin, 27, in a fluid-tight manner.

The lower end of the outer steel tube, 21, is welded to the tool joint pin, 27, by suitable weld, 28.

As shown in the accompanying drawing, the tubular extension joint, 25, has an end portion, 18, of reduced outside diameter to fit into the end of the outer steel tube, 21; the tool joint pin, 27, has likewise an end portion, 19, of reduced diameter to fit into the lower end of the outer steel tube, 21.

The inner tube and outer tube, affixed as hereinabove described, to the extension joint and tool joint pin, respectively, thereby define a fluid-tight annular chamber, 22. A bore, 29, extending longitudinally upward from the annular chamber, 22, through the extension joint, 25', communicates with a radial bore, 30, in said extension joint, 25, providing thereby a passage for communication between the annular chamber, 22, and the outside; likewise, a bore, 31, extending longitudinally from the annular chamber, 22, into the tool joint pin, 27, communicates with a radial bore, 32, provides a passage for cornmunication between the annular chamber and the outside.

The ends of each radial bore, 30, 32, extending to the outside, are threaded and are provided with a suitable screw plug, 33.

A number of sleeves, 34-, separated by spacers, 35, are positioned in spaced relation from each other about the inner steel tube, 20, between the extension joint, 25, and the tool joint pin, 2 7, and said sleeves are fastened to the inner steel tube by preheating them and thereafter shrinking them into a pressure fit against the inner steel tub e, 2t V The outside diameter of the sleeves, 34, is substantially the same as the inside diameter of the outer steel tube, 21. A flat longitudinal section, 23, is provided on the outer surface of each sleeve, 34, to provide a fiuid passageway along the sleeve, between the sleeve, 34, and the inside Wall of the outer steel tube, 21.

A spacer, 35, of smaller outside diameter than the sleeve, 34, is positioned between adjacent sleeves.

The inside diameter of each spacer, 35, is larger than the outside diameter of the inner steel tube, 20, so as to permit such spacer, to slide longitudinally along and upon the inner steel tube, 20, between fixed sleeves, 34, to dampen or break the vibration harmonics.

In operation, my fiuid-paeked drill collar, illustrated in'PIGURES 2 and 3, is assembled as follows:

' A sleeve, 34, is preheated and mounted about the center of the inner steel tube, 20, so that it will shrink into a pressure fit against the inner steel tube, 20.

A spacer, 35, is then slidably arranged on each side of said sleeve, 34.

An additional sleeve, 34, is then mounted on each side of said spacers, respectively, by preheating said sleeve and permitting it to shrink into a pressure fit with the inner steel tube, 20, in spaced relation to said spacers, 35, respectively.

Additional spacers and sleeves are then arranged alternately about said inner steel tube, 29, extending to the threaded ends of the inner steel tube.

The extension joint, 25, is then preheated, and threadedly engaged to the inner steel tube, 20, where it will then shrink into a pressure fit about the inner steel tube, 25.

The outer steel tube, 21, is then preheated and placed about the inner steel tube, 20, in slidable contact with the sleeves, 34, and the end portion, 1.8, of reduced out- ,side diameter of the tubular extension joint, 25, where it will then shrink into a pressure fit about said end portion, 18, and said sleeves, 34, 34.

The beveled upper end of the outer steel tube, 21, is then welded to the tubular extension, 25, by suitable weld, 26. I

The tool joint pin, 27, is thenpreheated and threadedly engaged with the inner steel tube, 20, where it will shrink into a pressure fit with said tube.

The lower beveled edge of the outer steel tube, 21, is then welded to the end portion, 19, of reduced diameter, of the tool joint pin, 27, by suitable weld, 28, in a fluidtight manner. A tool joint box, 53, is then screw threaded to the upper end of the tubular extension joint, 25.

Depending upon the total weight desired, or the harmonic vibrations expected, a proper fluid is then selected, the lower plug, 33, is then inserted and the fluid is then introduced into the annular chamber of the drill collar, through the radial bore, 30, and the longitudinal bore, 29, until the annular chamber is' filled with such liquid. Thereupon a suitable screw plug, 33, is threaded into the radial bore, 30, and the boreis then sealed.

The selection of the proper fluid includes heavy as well as relatively light fluids, such as, for instance, mercury, oil, water, glycerine, fats, and'alcohol.

Additional control may be accomplished by adding to the liquid suspended steel needles, which will have a tendency to break harmonic vibrations and to safeguard the assembled string of drill pipes and drill collars.

A modified form of my invention is shown in FIG- URES 4, 5, and 6, wherein a combination of rubber sleeves, stretch-fitted about the inner, steel tube, 20, and a rubber sleeve slidably arranged about the inner steel tube, 20, is alternated with a steel sleeve, 34, preheated and mounted about the inner steel tube by pressure fit, and a steel spacer, 35, slidably arranged about the inner steel tube, 20. Specifically, as illustrated in FIGURES 4, 5, and 6, a rubber sleeve, 40, is stretch-fitted about the inner steel tube, 20, preventing its longitudinal movement.

.'A rubber slidable sleeve, 41, having a larger inside diameter than the outside diameter of the inner steel tube, 20, is then arranged about said inner steel tube.

A steel sleeve, 34-, is then preheated and disposed about the inner steel tube in a pressure fit.

A steel spacer, 35, is then slidably disposed about the inner steel tube adjacent to the steel sleeve, 34; another rubber sleeve, 40, is then stretch-fitted about said inner steel tube, 20, and the same alternate sequence is maintained and repeated as hereinabove stated, until the space between the extension joint, 25, and the tool joint pin, 27, is filled.

The extension joint, 25, and the tool joint pin, 27, are then preheated and threadedly affixed to the inner Steel tube, and welded to the outer steel tube, 21, as illustrated in FIGURES 3, 4, and 5 in the accompanying drawing.

A liquid of pre-selected consistency is then introduced into the annular space between the inner steel tube, 29, and the outer steel tube, 21, as hereinabove outlined, and the passageways for the liquid are sealed with suitable screw plugs, 33. v

A flat portion, 45, is provided longitudinally in the cylindrical Surface of the rubber sleeve, as shown in the accompanying drawing; in the alternative, a groove may be provided longitudinally in the cylindrical surfaceof the rubber sleeve, 49, or a hollow steel needle may be inserted into each rubber sleeve, 45, longitudinally to provide a continuous passageway for liquids from the extension joint, 25, to the tool joint pin, 27

A modification of my assembly is shown in FIGURES 5 and 6 providing for stationary spacers, 42, between sleeves, 34, and the sleeves nearest the tool joint pin and tubular extension joint. If such stationary spacers are used, it will not be necessary to preheat and pressure-fit the sleeves which will be positioned between stationary spacers, 42. The spacers, 35, are slidably disposed about the stationary spacers, 42, so as to permit longitudinal movement between adjacent sleeves, 35, 35, or, between steel sleeves and rubber sleeves as shown in FIGURES 4, 5 and 6.

FIGURES 7, 9, and 10 of the accompanying drawing, show a modified form of my invention, wherein the inner steel tube, 20, is welded to the tool joint pin, 27; the steel sleeves, 34-, 34, and steel spacers, 35, 35, are then alternately disposed about the inner steel tube, 26, as hereinabove described; the outer steel tube, 21, is then preheated and slid into place about the steel sleeves, 34, 34, and by pressure fit fixed in position; the lower end of said outer steel tube, 21, is then welded to the tool joint pin, 27.

The upper end of the inner steel tube, 20, is then threadedly engaged with the preheated extension joint, 25, and pressure shrunk so as "to form a fluid-tight connection; the outer steel tube, 21, is then welded about the beveled end, 52, to the section of reduced diameter of the extension joint, 25. A tool joint box, 36, is then screw threadedly affixed to the upper portion of the extension joint, 25, and a lift plug, 53, may then be threadedly attached to the upper end of the tool joint box for handling by the elevators.

It is understood that the tool joint box may be welded to the extension joint.

FIGURES 8 and 11 of the accompanying drawing show a modified form of my invention, where the construction of my device permits welding of all joints of the drill collar while still accomplishing the dampening of harmonic vibrations by the means described in this specification.

In assembly, a tubular extension joint, 55, having the same outside diameter as, or a diameter slightly smaller than, the inside diameter of the outer steel tube, 21, to be used, and the tool joint pin, 27, are connectcd'by suitable weld, 54, 54, to the ends of the inner steel tube, 29. The tubular extension joint, 55, has the bores described in this specification for providing passageways for the liquids to be used in the assembly.

The outer steel tube, 21, is then preheated and pressure shrunk against the reduced diameter portion of the tool joint pin, 27, and the cylindrical surface of the ex tension joint, 55, by sliding said outer steel tube, 21, into position from the end carrying the extension joint, 55. As soon as the outer steel tube, 21, is normalized and pressure fitted, the beveled ends, 53, 53, are then welded to the tool joint pin, 27, and the extension joint, 55. t

A tool joint box, 36, is then welded to the top of the extension joint, 55.

Steel, or other alloy, shavings, or needles will then be pre-mixed with the liquid selected for filling the annular space between the inner steel tube, 20, and outer steel tube, 21, such as rubber or asphalt in its heated liquid state, and the annular space is then filled either through the bores contained in the extension joint, 55, or the tool joint pin, 27. The bores are then sealed with a screw plug, 33, as shown.

FIGURES 7 and 8 best illustrate the variety accomplished by my invention, which is accomplished by the use of an extension joint having a reduced diameter portion, as shown in FIGURE 7, and whose outside diameter is otherwise the same as that of the outer steel tube used, and the extension joint illustrated in FIGURE 8 of the same or slightly smaller diameter has the inside diameter of the outer steel tube, thereby permitting any selected attachment of the elements of the drill collar either by threading, or welding, or both.

All of the forms of my invention, illustrated or described in this specification, excepting only the modified form of my invention illustrated in FIGURE 8 of the drawing, permit the use of steel sleeves, 34, 34, of sufficiently large outside diameter as to form a pressure fit when the outer steel tube, 21, having been preheated, is cooled or normalized upon being disposed about the inner steel tube. The drill collar is thereby stabilized and given additional strength against lateral bending of the outer steel tube.

FIGURE 8 illustrates the use of a collar-type tool joint box in conjunction with my extension joint, permitting the use of elevators in handling the drill collar.

The use of my invention described above accomplishes by the use of the sleeves and spacers made of pre-selected materials and the pro-determined density of the liquid used, premixed with such solids as may be suitable for the particular use to which the drill collar may be subjected, four basic aims of the industry, namely:

(1) An effective means of breaking and dampening harmonic vibrations originating at the drill bit by reason of the use of a plurality of materials of dilferent density filling the annular space between the inner steel tube and the outer steel tube;

(2) By providing a heavily weighted drill collar, there- ,by increasing the effectiveness of the drill column and reducing thereby the number of failures due to strain and metal fatigue in the drill column, and giving added stability against bending stresses;

(3) By providing, in eifect, unlimited selectivity in the composition of the filler material deposited in the annular space between the inner steel tube and the outer steel tube; and

(4) By permitting a Wide range of selecting the preferred method of assembling and joining the various elements of the drill collar by reason of the flexibility inherent in the tubular extension joints used in my device.

It is understood that various forms of my invention may be used or util zed embodying the principles of my invention, without departing from the spirit of my invention.

I claim:

1. A device of the class described, comprising an inner steel tube, an outer steel tube disposed about said inner steel tube and forming between the outer surface of the inner steel tube and the inner surface of the outer steel tube an annular space, a tool joint pin having a portion of reduced outside diameter screW-threadedly engaged with the inner steel tube and affixed to the outer steel tube by welding the same to the portion of reduced diameter, a tubular extension joint having a portion of reduced diameter screw-threaded1y engaged to the inner steel tube and aflixed to the outer steel tube by welding the same to the portion of reduced diameter, such threaded and welded joints, respectively, being of fluid-tight character thereby forming a fluid-tight annular space between the outer surface of the inner steel tube and the inner surface of the outer steel tube and said tool joint pin and tubular extension joint, respectively, having bored passageways communicating between the annular space and the outside and suitable for sealing by screw plug, a plurality of sleeves of cylindrical shape having a longitudinal fiat portion disposed along their outer surface, spaced at pro-determined distance apart about said inner steel tube and rigidly afiixed thereto and having an outer surface rigidly affixed to the inner surface of the outer steel tube, and a plurality of spacers disposed between adjacent sleeves slidably about the inner steel tube longitudinally between adjacent sleeves and having an outside diameter smaller than the inside diameter of the outer steel tube.

2. A device of the class described, comprising an inner steel tube, an outer steel tube disposed about said inner steel tube and forming between the outer surface of the inner steel tube and the inner surface of the outer steel tube an annular space, a tool joint pin having a portion of reduced outside diameter screw-threadedly engaged with the inner steel tube and affixed to the outer steel tube by welding the same to the portion of reduced diameter, a tubular extension joint screw-threadedly en-,

.gaged to the inner steel tube and aflixed to the outer steel tube by welding the same to the outer surface of said extension joint, such threaded and welded joints, respectively, being of fluid-tight character thereby, forming a fluid-tight annular space between the outer surface of the inner steel tube and the inner surface of the outer steel tube and said tool joint pin and tubular extension joint, respectively, having bored passageways communicating between the annular space and the outside and suitable for sealing by screw plug, a plurality of sleeves of cylindrical shape having a longitudinal flat portion disposed along their outer surface spaced a pre-determined distance apart about said inner steel tube and rigidly afiixed thereto and having an outer surface rigidly aflixed to the inner surface of the outer steel tube, and a plurality of spacers disposed between adjacent sleeves slidably about the inner steel tube longitudinally between adjacent sleeves and having an outside diameter smaller than the inside diameter of the outer steel tube.

3. In a fluid-tight drill collar adapted to be included in a drill string the combination of an inner steel tube surrounded by an outer steel tube forming an annular chamber therebetween and having ends sealed by suitable means comprising a tool joint affixed to the tubes at each end thereof, and a plurality of sleeves of cylindrical shape having a longitudinal'flat portion disposed along their outer surface aflixed about said inner steel tube in longitudinally spaced relation to each other and each having an outer cylindrical surface in press-fitted contact with the inner surface of the outer steel tube, a plurality of spacers of less length that the space between the sleeves being slidably mounted about said inner steel tube, each spacer being slidably disposed between two adjacent sleeves, a fluid of pro-determined density filling said annular chamber, and means in said tool joint adapted to pass fluid into said annular chamber and to be sealed after the fluid is supplied to the chamber.

4. A fluid-tight drill collar including an inner steel tube surrounded by an outer steel tube forming a fluidtight annular chamber therebetween and having ends sealed by suitable means comprising a tool joint aflixed to the tubes at each end thereof, a plurality of sleeves of cylindrical shape having a longitudinal fiat portion disposed along their outer surface affixed between the inner steel tube and the outer steel tube in spaced relation to each other along said inner steel tube, a plurality of spacers of less length than the space between the sleeves, mounted slidably about inner steel tube, each spacer being' disposed between two adjacent sleeves, and a fluid of pre-se lected density filling said annular chamber, and means in said tool joint adapted to pass fluid into said annular chamber and to be sealed after the fluid is supplied to the chamber.

0 ca References Cited by the Examiner UNITED STATES PATENTS 259,048 6/82 Richardson 285-137 5 1,053,622 2/13 McAllister 285137 2,594,617 4/52 Boice 175320 2,814,462 11/57 De Jarnett l75-320 CHARLES E. OCONNELL, Primary Examiner.

10 BENJAMIN BENDETT, Examiner. 

1. A DEVICE OF THE CLASS DESCRIBED, COMPRISING AN INNER STEEL TUBE, AN OUTER STEEL TUBE DISPOSED ABOUT SAID INNER STEEL TUBE AND FORMING BETWEEN THE OUTER SURFACE OF THE INNER STEEL TUBE AND INNER SURFACE OF THE OUTER STEEL TUBE AN ANNULAR SPACE, A TOOL JOINT PIN HAVING A PORTION OF REDUCED OUTSIDE DIAMETER SCREW-THREADEDLY ENGAGED WITH THE INNER STEEL TUBE AND AFFIXED TO THE OUTER STEEL TUBE BY WELDING THE SAME TO THE PORTION OF REDUCED DIAMETER, A TUBULAR EXTENSION JOINT HAVING A PORTION OF REDUCED DIAMETER SCREW-THREADEDLY ENGAGED TO THE INNER STEEL TUBE AND AFFIXED TO THE OUTER STEEL TUBE BY WELDING THE SAME TO THE PORTION OF REDUCED DIAMETER, SUCH THREADED AND WELDED JOINTS, RESPECTIVELY, BEING OF FLUID-TIGHT CHARACTER THEREBY FORMING A FLUID-TIGHT ANNULAR SPACE BETWEEN THE OUTER SURFACE OF THE INNER STEEL TUBE AND THE INNER SURFACE OF THE OUTER STEEL TUBE AND SAID TOOL JOINT PIN AND TUBULAR EXTENSION JOINT, RESPECTIVELY, HAVING BORED PASSAGEWAYS COMMUNICATING BETWEEN THE ANNULAR SPACE AND THE OUTSIDE AND SUITABLE FOR SEALING BY SCREW PLUG, A PLURALITY OF SLEEVES OF CYLINDRICAL SHAPE HAVING A LONGITUDINAL FLAT PORTION DISPOSED ALONG THEIR OUTER SURFACE, SPACED A PRE-DETERMINED DISTANCE APART ABOUT SAID INNER STEEL TUBE AND RIGIDLY AFFIXED THERETO AND HAVING AN OUTER SURFACE RIGIDLY AFFIXED TO THE INNER SURFACE OF THE OUTER STEEL TUBE, AND A PLURALITY OF SPACERS DISPOSED BETWEEN ADJACENT SLEEVES SLIDABLY ABOUT THE INNER STEEL TUBE LONGITUDINALLY BETWEEN ADJACENT SLEEVES AND HAVING AN OUTSIDE DIAMETER SMALLER THAN THE INSIDE DIAMETER OF THE OUTER STEEL TUBE. 